In her latest attack, Ms Honeyball said: "It appears that Ms Kelly is at last doing the decent thing and going, because she cannot support the HFE Bill due to come before the House of Commons soon for its third reading.

"It is well known that Kelly not only opposed but forced a free vote during the second reading on three of the Bill's most important clauses: screening embryos for diseases to allow saviour siblings, the creation of human-animal hybrid embryos for vital medical research and ending the requirement for a father in IVF treatment.

"All this is, of course, entirely in line with the Catholic Church's attitude. Kelly put her religion before the wishes of those who elected her during the second reading of the Embryology Bill. Her decision to go means that this, thankfully, will not happen again,"